After loading the GD32duino bootloader from STM32 ST-Link utility, I compiled and uploaded via USB a blink sketch from Arduino (selecting GD32F103C8 board).
Then, I tried again to connect the board via SWD, from STM32 ST-Link utility. The connection worked only after setting 'connect under reset' - pressing and releasing RESET while connecting to target. I couldn't connect otherwise..Maybe this info is helpful to someone..

RogerClark wrote:
Often the agents fees make things much more expensive....

I had an agent about 15 years ago, He produced PC103 boards. I sent him a list of computer stuff I wanted and he would get bundle it all together and ship it. He usually negotiated a fee from the seller so often it did not cost me more than I had been quoted by the manufacturer, but we were talking combined orders of $20K+ .

I would not mind buying 100 blue pill GD32 boards If I could get them at a reasonable price I buy the blue pills in 20s. I could just stick em on ebay I am sure there is a premium to be had by their increased speed even @ 72MHz